Title

DNS is very slow and lookup domain name timeout in standalone k8s.

General Information

• Cilium version (run cilium version): 1.1.0
• Kernel version (run uname -a):Linux ip-10-12-3-68 4.13.0-45-generic Updating cni #50~16.04.1-Ubuntu SMP Wed May 30 11:18:27 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
• Orchestration system version in use (e.g. kubectl version, Mesos, ...): k8s 1.10.2
• Link to relevant artifacts (policies, deployments scripts, ...)
• Upload a system dump (run curl -sLO releases.cilium.io/tools/cluster-diagnosis.zip && python cluster-diagnosis.zip sysdump and then attach the generated zip file)

How to reproduce the issue

1. Start a standalone k8s node
2. Our program will keep downloading images from different urls
3. After a while(3 ~ 5 hours), our program will report lookup domain name timeout
4. If we use flannel, that won't happen